Heart failure is an abnormality of cardiac function that causes cardiac output to fall below a level adequate to meet the metabolic demand of peripheral tissues. Heart failure is often referred to as congestive heart failure (CHF) due to the accompanying venous and pulmonary congestion. Heart failure may have a variety of underlying causes, including ischemic heart disease (coronary artery disease), hypertension (high blood pressure), and diabetes, among others. It has been observed that respiratory disruption can be particularly serious for patients concurrently suffering from cardiovascular deficiencies, such as heart failure. Unfortunately, disordered breathing is often undiagnosed. If left untreated, the effects of disordered breathing may result in serious health consequences for the patient.
Because of the need for early evaluation of heart failure and/or disordered breathing symptoms, an effective approach to monitoring and early diagnosis is desired. Acquiring accurate physiological sensor information may allow for early intervention, preventing serious heart failure decompensation and hospitalization.